CPUsUndertaking the task of building your own PC can be overwhelming. You need a variety of components and you need all your components to work together. In this post, I’m going to take a look at one of the most important PC components – the Central Processing Unit, or CPU.

This article is part of an educational series about PC components. Click here to see the rest of the series.

Table of Contents:

      1. CPUs: The brains of the operation
      2. CPU technical specifications
      3. Brands
      4. Match the CPU to the motherboard
      5. The right CPU for the right build

CPUs: The brains of the operation

I’ll start with the very general overview. Your CPU is the brain of your computer. It does all the heavy thinking for every task, other than the computational work done by your video card’s graphical processing unit (GPU). Your CPU needs to have enough power, enough multitasking capacity, and enough communication capacity for the jobs you ask of it.


CPU technical specifications

It can be confusing to sort through the various CPU statistics in hopes of finding the ones that impact your PC build. So, here’s a quick overview of the primary specifications of a CPU and what they mean.

CPU lanes

Your CPU will have dedicated connections available for some of the peripheral component interconnect express (PCIe) slots on your motherboard. These connections are the CPU lanes, and there are a finite number of them that can be assigned. Your video card will take most of them up. If you decide to go wild with additional PCIe components, you may exceed the lanes available and lose some functionality. So keep the number of lanes in mind when you add components.

CPU cores

Your computer takes a big computational task and breaks it into multiple smaller sub-tasks. When all of the sub-tasks are done, your big task is finished. Your CPU cores are physical components on the CPU itself, and each of them can work on an individual task. So more cores means more simultaneous computational tasks being done. And that means faster overall processing.

Clock speed

The clock speed Is the most direct measurement of your CPU’s raw speed. It measures the number of times per second your CPU cycles, and the more cycles per second your chip can do, the faster it goes. It’s not the only defining factor in terms of speed, but it is one of the most important ones. Some CPUs have the capacity to run the chip at even higher clock speeds (overclocking), If that sounds intriguing to you, make sure you read up on what it entails and the possible drawbacks. Overclocking is not for the casual PC builder.


Unlike the CPU cores, threads are not physical parts of CPUs. They are virtual components that manage a related pile of tasks that the cores are working on. Your threads make sure that the related tasks have the resources they need and are ready in time for dependent tasks to use them. The threads pass the tasks to the CPU cores.


The cache is memory that is dedicated for the CPU’s exclusive use. Since it is physically connected to the CPU, the cache is faster to access than the main system memory. More cache means less time spent waiting for data from the main memory. There are usually two caches: L1 and L2. You’ll be looking at the L2 cache when shopping for a CPU.


This is a number that doesn’t mean much until it means everything, and you have a catastrophic hardware failure. Okay, I’m being a little overdramatic. Most PC users won’t have their CPU get hot enough to burst into flame. But as you push the performance of your CPU, it will heat up. And if you add in the heat coming from the other PC components, you can face heat issues. Make sure you have a cooling solution that will keep your CPU at an optimal operating temperature.


You have two CPU designers to choose from: AMD and Intel. Each generation of CPU sees these two companies competing to have the best CPUs on the market. Right now, AMD seems to have a slight edge, but everything could change in six months. The good news for you is that either is a great choice for your PC build. It’s really a matter of the technical details of the chips, not the company that designed it.

Match the CPU to the motherboard

It may not occur to you that there are different motherboards for the different chipsets. That’s why you need to check which chipset your motherboard is built for before you buy a CPU. You’re looking for the type of socket that your motherboard has. Because an intel CPU won’t fit in an AMD socket, and vice versa.

The right CPU for the right build

Your CPU choice is shaped by the overall purpose of the PC. Here are a couple of scenarios for your consideration.

Media centre PC

You want a new computer to serve as the media hub for your living room. Raw power won’t be a requirement, and neither will speed. You would be better served to pick an affordable CPU and save some money.

Home office PC

Your line of work is the important variable in this situation. If you’re only writing emails and documents, a high-powered CPU won’t have much of an effect. On the other hand, if you’re doing graphic design or multimedia creation and editing, you’ll want a CPU that can handle the heavy workload. But generally, you can select a CPU that balances power and affordability.

Gaming PC

This is the scenario that demands all the CPU power you can throw at it. Your CPU is going to run hot, especially if you decide to overclock, so take the temperature rating as a guiding principle in your build. Your gaming CPU will be the crowning jewel of the system (okay maybe it will be tied with your video card for most impressive component). Every part of your gaming PC build will be chosen to optimize the speed, power and communication of the CPU to the rest of the system.

CPU Checklist

A good component shopping trip depends on getting the right part that will work with the rest of your PC. This is a basic list of the parts that your new CPU has to be compatible with.

  • Motherboard socket
  • CPU cooler
  • Motherboard chipset
  • PC cooling accessories (Do you need more thermal paste?)

Next steps 

If you want to learn more about other PC components, make sure to check out our series on how to build your own PC. You can find all the PC components you would need, including CPUs, at Best Buy. To learn more about building your own PC and PC components, be sure to check out all the posts in this series.


Chris is a novelist, avid gamer, tech enthusiast, and proud dad of a 13-year-old video game master.


  1. While on the topic of PC components, I wonder if Best Buy will offer GPUs to customers directly in the store in the near future instead of only online where time is of the essence more so than the store?

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